Can I use Hair Loss Treatment as part of the Soft Power DTV in Thailand?

Hair loss treatment might work. I recently had hair surgery in Chiang Mai and it is a one year program of hair treatment. The plan includes the surgery, PRP injections, red lighting therapy, hair spa (hair washing), and medications. A doctor at a hair clinic should be able to design and write up a long term treatment plan. Of course, there are no guarantees that immigration would accept it, but it’s worth a shot.

I’m on DTV soft power for physical therapy. I was approved with a 10 session (5 week) treatment plan.

Mesotherapy is a medical treatment for hair loss so it should come under the medical DTV option. You will need to show a 6 months plus treatment plan. One session each 4 months? ? you mean one session a month ? a session every 4 months will very likely lead to a rejection.